March 2, 2014

Horses and other livestock pose a significant threat to the future of the panda, as they are beating the endangered creatures to the bamboo pandas rely on for sustenance, according to research appearing in this week’s edition of the Journal for Nature Conservation.

“Across the world, people are struggling to survive in the same areas as endangered animals, and often trouble surfaces in areas we aren’t anticipating,” said Jianguo ‘Jack’ Liu of Michigan State University (MSU). “Creating and maintaining successful conservation policy means constantly looking for breakdowns in the system. In this case, something as innocuous as a horse can be a big problem.”

Liu and his colleagues investigated how an emerging livestock population in the Wolong Nature Reserve in China was affecting that region’s giant panda population. They took empirical data from field surveys, remotely sensed images and GPS color tracking to review the distribution of horses in the panda habitat, the space usage and habitat selection patterns of both types of creatures, and the impact of horses on the availability of bamboo.

“We discovered that the horse distribution overlapped with suitable giant panda habitat,” they wrote in their study. “Horses had smaller home ranges than pandas but both species showed similarities in habitat selection. Horses consumed considerable amounts of bamboo, and may have resulted in a decline in panda habitat use.”

The research highlights the need for new policies that address this growing threat to the endangered giant panda. While timber harvesting has for years been the primary threat to the 1,600 remaining pandas, their specific food and habitat needs (they only eat bamboo and live in regions with gentle slopes that are far away from people) mean that they can be greatly impacted by encroaching livestock populations.

MSU Center for Systems Integration and Sustainability (CSIS) doctoral student Vanessa Hull, who has been living in the Wolong Nature Reserve off and on for the past seven years, was the first to observe horses eating bamboo while tracking pandas equipped with GPS collars.

“It didn’t take particular panda expertise to know that something was amiss when we’d come upon horse-affected bamboo patches. They were in the middle of nowhere and it looked like someone had been in there with a lawn mower,” she explained. Following her observations, Hull checked around and found that some of Wolong’s farmers had begun raising horses, which were allowed to graze unattended until they were to be sold.

“It was an idea whose popularity skyrocketed,” the university said. “In 1998, only 25 horses lived in Wolong. By 2008, 350 horses lived there in 20 to 30 herds. To understand the scope of the problem, Hull and her colleagues put the same type of GPS collars they were using to track pandas on one horse in each of the four herds they studied.”

Over the course of a year, they compared the activity of the horses with three adult collared pandas in some of the same regions of the reserve, and also combined that information with habitat data. They found that horses not only dined on bamboo, but also preferred the same type of sunny, gently sloped living spaces as pandas.

“Pandas and horses eat about the same amount of bamboo, but a herd of more than 20 horses made for a feeding frenzy, decimating areas the reserve was established to protect,” the university said, adding that the horse issue has since been solved and the livestock had been banned from Wolong by the reserve’s managers.

Image 2 (below): Vanessa Hull with horses in Wolong. Credit: Michigan State University